v3.5.0.2
Debt Debt, Senior Notes (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2016
May 09, 2016
6.375% Senior Notes Due 2024 [Member] | Debt Instrument, Redemption, Period One [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 4.781%  
6.375% Senior Notes Due 2024 [Member] | Debt Instrument, Redemption, Period Two [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 3.188%  
6.375% Senior Notes Due 2024 [Member] | Debt Instrument, Redemption, Period Three [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 1.594%  
6.125% Senior Notes due 2021 [Member] | Debt Instrument, Redemption, Period One [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 4.594%  
6.125% Senior Notes due 2021 [Member] | Debt Instrument, Redemption, Period Two [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 3.063%  
6.125% Senior Notes due 2021 [Member] | Debt Instrument, Redemption, Period Three [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 1.531%  
6.125% Senior Notes due 2021 [Member]    
Debt Instrument    
Debt Instrument, Face Amount   $ 250
Existing Senior Notes $ 550  
6.125% Senior Notes due 2021 [Member] | Debt Instrument, Redemption, Period One [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 106.125%  
Debt Instrument, Redemption Price, Percentage of Principal Amount that can be redeemed 35.00%  
6.375% Senior Notes Due 2024 [Member]    
Debt Instrument    
Debt Instrument, Face Amount   $ 450
6.375% Senior Notes Due 2024 [Member] | Debt Instrument, Redemption, Period One [Member]    
Debt Instrument    
Debt Instrument, Redemption Price, Percentage 106.375%  
Debt Instrument, Redemption Price, Percentage of Principal Amount that can be redeemed 35.00%